Merge in various enhancements to bisect.pl and bisect-runner.pl

diff --cc pod/perldelta.pod
index 50aeaba,50aeaba..6ea5651
--- 1/pod/perldelta.pod
--- 2/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@@ -243,16 -243,16 +243,43 @@@ Most of these are built within the dire
  entries for each change
  Use L<XXX> with program names to get proper documentation linking. ]
  
--=head3 L<XXX>
++=head3 F<bisect.pl> enhancements
++
++The git bisection tool F<Porting/bisect.pl> has had many enhancements.
  
  =over 4
  
  =item *
  
--XXX
++Can optionally run the test case with a timeout.
++
++=item *
++
++Can now run in-place in a clean git checkout.
++
++=item *
++
++Can run the test case under C<valgrind>.
++
++=item *
++
++Can apply user supplied patches and fixes to the source checkout before
++building.
++
++=item *
++
++Now has fixups to enable building several more historical ranges of bleadperl,
++which can be useful for pinpointing the origins of bugs or behaviour changes.
  
  =back
  
++It is provided as part of the source distribution but not installed because
++it is not self-contained as it relies on being run from within a git
++checkout. Note also that it makes no attempt to fix tests, correct runtime
++bugs or make something useful to install - its purpose is to make minimal
++changes to get any historical revision of interest to build and run as close
++as possible to "as-was", and thereby make C<git bisect> easy to use.
++
  =head1 Configuration and Compilation
  
  XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools